Three billion WhatsApp users are at risk - an expert has developed a tool that could spy on everyone, and you would never know about it
Three billion WhatsApp users are at risk - an expert has developed a tool that could spy on everyone, and you would never know about it
Very simplified: assume you send somebody a signal messages every second and observe the timing of the “delivered” icon. They do the same but the messages are invisible and they time the icon very exactly.